to sea in an offshore breeze, had been thoroughly cleaned by our army as soon as the Spaniards evacuated Cuba in 1898, but still our soldiers had kept dying of yellow fever there. Everything that medical science could suggest was done to stop the spread of the disease, but without effect. Thousands sickened and hundreds died, while the doctors stood by, as one of them declared, "in utter perplexity and wonder."
No one knew how yellow fever was spread, though its ravages had been only too well known for two centuries and more. It had killed over thirty-six thousand people in Havana and a hundred and thirty thousand in Spain; it had swept our coast from Massachusetts to Florida, killing one person out of every ten in Philadelphia in 1793, and over forty thousand in New Orleans between then and the end of the nineteenth century. Though other diseases, notably tuberculosis, have caused and still are causing much more direct suffering and loss of life, they were less feared because they lacked the terror of the unknown. When yellow fever broke out in a city, it was as if the very Angel of Death had come, walking invisible and slaying without cause. Then followed wild stampedes, brutally checked by "shotgun quarantines," looting, debauchery, and a wide-spread paralysis of business, causing altogether a loss of life and property impossible to compute.
Two things held yellow fever in check; frost stopped it, and those that recovered from the first attack were immune for the rest of their lives. Several regiments of these "immunes" were raised during the Spanish-American War, but there were not enough of them to garrison,
